4 Answers
4

create a new commit which applies reverse changes. This is the preferred option as it doesn't changes history on a public repository

Remove the commits and force push them.

The first option can be achieved by using git revert

git-revert - Revert some existing commits

Given one or more existing commits, revert the changes that the related patches introduce, and record some new commits that record them.

An example would be git revert -n HEAD~5..HEAD. This command creates 5 new commits, each of which undoes one of the last 5 commits of the currently checked out branch.

The second option would be to actually remove the commits. Note that this changes history in the repository. So anyone who has already pull the changes will probably be rather surprised and things can get messy quickly. That said, you can do

git reset --hard HEAD~5
git push --force

The first command will wipe any uncommitted changes in your current working copy. and reset your local repository to the state of the current HEAD - 5 commits. The second command will force-push to the default remote (i.e. GitHub) There, any changes diverging from your current local repository are overwritten.

A note of warning again: If you don't really know what you are doing, don't use this option as it can lead to data loss for you or others if not done right. Use the first option instead as it will transparently remove changes but without the nasty side-effects of history-rewriting.

Can you explain what HEAD~5..HEAD does?
– Rutger HofsteOct 12 '17 at 16:10

3

@RutgerHofste It described the range of commits between HEAD (i.e. the currently checkout commit) and 5 commits before HEAD. The git revert would thus create revert commits for the last 5 commits. Similarly, the git reset command would move the current branch 5 commits back. See this blog post for a nice explanation on how to specify relativ commits for commands.
– Holger JustOct 12 '17 at 16:45